Fluid pump



A. .KOSIAN FLUID PUMP Feb. 25, 1941,

Filed May 28, 1938 J H I INVENTOR A TTOENEY ARTHUR KOS/AN PER I PatentedFeb. 25, 19416 PUMP Arthur Kosian, Chicago, Ill. Application May 28,1938, Serial No. 210,657

1 Claim.

This invention relates to improvements in rotary fluid pumps and has,for oneof its principal objects, the provision of such a pump whichshall be simple, compact and economical to manufacture, composed of aminimum of parts, easy of operation and not likely to get out of order.

One of the important objects of this invention is the provision of arotary fluid pump that has both its inlet and outlet for the fluid inthe driven shaft, thereby gaining a uniformity of appearance andmechanical efficiency.

Another object of this invention is the provision of a rotary fluid pumpthat is self-lubricating especially when it is pumping oil or when it isoperating in the capacity of,a compressor in a refrigerating system.

Another important object of this (invention is the provision of anirregular eccentric rotor operating in conjunction with four doubleabutments in a surrounding housing to produce the suction and pressureof this fluid pump.

Other and further important objects of the invention will be apparentfrom the disclosures in the accompanying drawing and followingspecification.

The invention, in a preferred form, is sho in the drawing andhereinafter more fully described.

In the drawing:

Figure 1 is an end view of the pump with the outer casing removed.

' Figure 2 is an irregular section taken on the line 2-2 of Figure 1.

Figure 3 is the irregular eccentric rotor removed from the pump.

Figure 4.1s a detail section of one setoi the abutments which are in thehousing surrounding the rotor.

As shown in the drawing:

The reference numeral I 0 indicates generally the outer casing orhousing of the improved rotary fluid pump of this invention.

Inside the casing I0 is the suction and compression cylinder I2 whichhouses an irregularly shaped eccentric rotor l4 driven by the shaft It,

the key l8keeping same in locked relationship..

As best shown in Figure 2, there is on the in- 50 take side of the pumpa fluid seal 20 which pre- Aplurality of sets of double abutments :4 m55 positioned in slots around the pump casing and extend into andcontact the rotor I4, these abutments being spring-pressed asillustrated at 26. An inlet channel for oil or other fluid to be pumpedis provided at 28, said inlet channel passing into and runninglongitudinally centrally of the shaft I6 and terminating in a pluralityof branches as shown at 30. The fluid is drawn into these inlet channelsby the suction created by the irregular rotatable eccentric I4 and isthen put under compression by the same eccentric rotor as the abutments24' operate in closing off said channels. While under compression, thefluid will travel out the outlet channels 32, thence to the center ofthe shaft again, as at 34, and out. The shaft I6 is so bored that theoutlet part 34 is of slightly greater diameter than the inlet part 36.Between these two cavities is positioned a separating wall 38 whichenables the intake and outgo of the fluid to be carried through thehollow portion of the shaft. As the fluid is pumped out, some of itcommunicates with the flttings for the abutments through an auxiliarychannel 40 and circular groove in the housing It), and it is evidentthat this added pressure of fluid on the outer edges of the abutments 24will be supplementary to the action of the springs 26 and provide abetter operating contact of the inner rounded ends of the abutments 24with the rotor l4 at points 42. e As best shown in Figure 3, a circularor similarly shaped groove 44 is provided in one face of the irregulareccentric rotor element I4, and a channel 46 leads from one of theoutlet ducts 32 to this groove 44. In this manner, the pressure whichexists in the outlet portion of the pump is communicated directly, bymeans of the fluid being pumped, to the channel or groove 44, and thearea of this groove 44 is designed to be exactly the same as the area ofthe end of the driving shaft l6 so that the pressure which is exerted onthe end of the driving shaft and the partition 38 during pumping isexactly counteron the which might otherwise take place on account of thevery considerable internal end pressures often built up in a pump ofthis type.

It will be noted that ninety degrees of the operating surface of therotor I4 is formed on the arc 'of a circle having the center of thedriving shaft as its center, and the opposite ninety degrees of theperiphery of the rotor is also formed on a circle having the same centerbut with a slightly smaller radius. The two intermediate ninety degreearcs are also circular but are not concentric with the other twosurfaces, the joining arcs being so designed as to form as smooth aspossible a connection between the first-mentioned arcuate surfaces. Thelengths of the arcs may bevaried somewhat, as the structure is notcritical. The abutments 24 are intentionally placed at an angle to theradius of the pump, this offsetting eifecting a better operation on highpressure inasmuch as there is not nearly so great a tendency tosidethrust against the abutments when they are so positioned as todistinguish from a radial positioning, and the ends of the abutmentswhich contact the cammed surface of the rotor need not be forced througha perpendicular motion when the pump is in operation.

As best illustrated in Figure 4, there are two parts in each abutment,there being a projection 48 at the top of each part, this projectionbeing semi-cylindrical in cross-section, and when the two parts areproperly positioned with relation to each other, the helical spring 26surrounds these two semi-cylindrical projections as best shown at 48 inFigure 2, thereby connecting the parts and also ail'ording asatisfactory seat for the lower end of the spring, the upper end ofwhich is positioned in a recess in the casing wall as shown. A one-pieceabutment will operate satisfactorily in this connection although it hasbeen found by experience that these double structures effect a bettersealing action for a greater length of time.

' The space between the inner wall of the cylinder l0 and that portionof the rotor having the largest radius can be quite small, and in fact,

the smaller this space the better resultant sealing and pumping action.

All parts of the device are automatically lubricated especially when oilor any liquid containing oil is being pumped, and theapparatus isparticularly emcient as a vacuum pump. When operating on liquids, a verysteady stream is produced, there being practically no undesirablepulsation, and this together with the compact size of the device and theminimum number of parts make for an ideal apparatus of this type.

This application, particularly with reference to the pump structure,-comprises an'improvement over the pump portion of my previousapplication for patent on Hydraulic clutch and power transmission, flledAugust "I, 1937, Serial No. 157,889.

Iam aware that many changes may be made and numerous details ofconstruction varied throughout a wide range without departing from .theprinciples of this invention, and I, therefore,

do not purpose limiting the patent granted hereon otherwise than asnecessitated by the prior art.

I claim as my invention: A rotary pump, comprising a driving shaft, arotor mounted on the end of the shaft generally eccentric thereto, saidrotor having diametrically opposite portions concentric with said shaftbut of different radii, a cylindrical housing for the rotor, abutmentsslidably mounted in the housing walls at an angle to radii thereof, andhaving their inner ends contacting the rotor, each abutment comprising apair of rectangular plates, a half round lug integral with the outeredge of each plate, said lugs being juxtaposed to form a two-partcylinder, helical springs seated on the cylinders for impelling the endsof the abutments against therotor, a fluid inlet channel in the pumpshaft, and a fluid outlet channel also in the pump shaft, an auxiliarychannel connecting the fluid outlet and the inner ends of the slots inwhich the abutments are positioned whereby fluid pressure in the outletmeans is communicated to the vanes and supplements the spring actionthereagainst.

ARTHUR KOSIAN.

